Fuel and air

P00FA — Turbocharger Outlet Pressure Sensor 'A' Circuit Low

Severity: medium Drive with care, to a shop

What P00FA means

The engine control module watches the voltage from sensor 'A', which measures air pressure at the turbocharger outlet. P00FA is set when that signal falls below the expected range, due to an open or shorted-to-ground circuit, a failed sensor, or a real boost problem. The ECM uses this reading to control boost and fueling.

Symptoms

  • Check engine light on
  • Reduced power and sluggish acceleration
  • Erratic throttle response around boost
  • Limp mode with limited power
  • Higher fuel consumption
  • Unusual turbo whistle or noise

Possible causes

  1. Failed turbo outlet pressure sensor
  2. Damaged or corroded sensor wiring or connector
  3. Open signal wire or short to ground in the circuit
  4. Charge-air leak or loose hoses and vacuum lines
  5. Faulty turbo actuator or sticking variable geometry mechanism
  6. Restricted intake path or intercooler
  7. Rarely, a faulty ECM

How to diagnose

  1. Read all codes and freeze frame data, then clear the code to see if it returns
  2. Inspect the sensor connector and harness for corrosion, chafing, moisture and loose pins
  3. Check charge-air hoses, clamps and the intercooler for cracks and leaks
  4. Compare the sensor reading with ambient pressure on a scan tool with the engine off
  5. Test the 5 V reference, ground and signal wire at the connector, and check the signal wire for a short to ground
  6. Compare specified and actual boost under load with live data
  7. Check actuator or vacuum control movement over its full range
  8. If the wiring is good, replace the sensor and recheck the readings

Common fixes

  • Replace the turbo outlet pressure sensor
  • Repair the wiring or replace a damaged connector
  • Fix charge-air and vacuum leaks
  • Clear restrictions in the intake path
  • Repair or replace the turbo actuator or variable geometry mechanism

Questions and answers

What does P00FA mean?

It means the circuit for turbocharger outlet pressure sensor 'A' is reading low. The cause is most often the sensor or its wiring.

Can I drive with P00FA?

Only briefly and carefully, such as to a shop. Power is usually limited, and long-term driving with poor boost control can harm the turbo and engine.

How do I fix P00FA?

Start by inspecting the wiring, connector and charge-air hoses, then test the sensor signal. If the circuit is good, the sensor is usually replaced.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.